It is estimated 2m cars are showing a flattering mileage figure, yet just 150 tamperers have been prosecuted

BUYERS are being warned not to trust the mileage readout of a used car until it has been checked by an independent firm. “Clocking” is on the rise again, and an investigation by our sister paper The Times reveals that little is being done to tackle it.

According to The Times, fewer than 150 prosecutions have been brought in the past five years, yet it is estimated that 2m cars have had their mileage reduced illegally.

The newspaper sent freedom of information requests to all Britain’s councils, which have responsibility for policing the crime of car clocking. The results should sound a note of caution for all used-car buyers: one in five councils had not investigated a single case since 2012.

A further one in three councils have not managed to pursue one case a year, even though individuals and garages openly offer to “correct” the mileage recorded by a car’s digital odometer. The service can cost as little as £40.

HPI Check, which verifies a car’s history and mileage, says one in 16 of the used cars it vetted last year had incorrect mileage; in 2014 the figure was one in 20.

Last year driving.co.uk investigated the rise of clocking. We found that many drivers use so-called mileage adjustment companies because they have bought cars on PCP and other lease deals, which typically include a mileage cap. The penalty for exceeding it can be as much as 12p a mile.

Then there are the rogue dealers and private sellers who lower the mileage to make a car more valuable.

Christopher Hargreaves, of Licensed Transport Uncovered, told The Times: “Councils are failing to protect the public by allowing criminal gangs and those who take out PCP agreements or low-mileage leasing deals to act with impunity, even though they have turned car-clocking into an industry.

“The lack of cases, both investigated and prosecuted, across the UK results in fraudsters knowing they have little to no chance of being caught.”

Even in the event of a successful prosecution, fewer than one in 10 trading standards departments inform people who bought from convicted clockers that their car could have a mileage discrepancy.

According to the Chartered Trading Standards Institute, budget cuts have made local teams unwilling to take the financial risk of bringing prosecutions.